must inquire
Regular verb: inquire - inquired- inquired

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must inquire
you must inquire
he must inquire
we must inquire
you must inquire
they must inquire 	I must be inquiring
you must be inquiring
he must be inquiring
we must be inquiring
you must be inquiring
they must be inquiring	I must have inquired
you must have inquired
he must have inquired
we must have inquired
you must have inquired
they must have inquired	I must have been inquiring
you must have been inquiring
he must have been inquiring
we must have been inquiring
you must have been inquiring
they must have been inquiring	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not inquire
you must not inquire
he must not inquire
we must not inquire
you must not inquire
they must not inquire 	I must not be inquiring
you must not be inquiring
he must not be inquiring
we must not be inquiring
you must not be inquiring
they must not be inquiring	I must not have inquired
you must not have inquired
he must not have inquired
we must not have inquired
you must not have inquired
they must not have inquired	I must not have been inquiring
you must not have been inquiring
he must not have been inquiring
we must not have been inquiring
you must not have been inquiring
they must not have been inquiring	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I inquire?
must you inquire?
must he inquire?
must we inquire?
must you inquire?
must they inquire? 	must I be inquiring?
must you be inquiring?
must he be inquiring?
must we be inquiring?
must you be inquiring?
must they be inquiring? 	must I have inquired?
must you have inquired?
must he have inquired?
must we have inquired?
must you have inquired?
must they have inquired? 	must I have been inquiring?
must you have been inquiring?
must he have been inquiring?
must we have been inquiring?
must you have been inquiring?
must they have been inquiring? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not inquire?
must you not inquire?
must he not inquire?
must we not inquire?
must you not inquire?
must they not inquire? 	must I not be inquiring?
must you not be inquiring?
must he not be inquiring?
must we not be inquiring?
must you not be inquiring?
must they not be inquiring? 	must I not have inquired?
must you not have inquired?
must he not have inquired?
must we not have inquired?
must you not have inquired?
must they not have inquired? 	must I not have been inquiring?
must you not have been inquiring?
must he not have been inquiring?
must we not have been inquiring?
must you not have been inquiring?
must they not have been inquiring?